Evaluation of four cation exchange HPLC instruments for the determination of hemoglobin A _1c : the devil is in the detail

Abstract Objectives The aim of this study was to evaluate 4 cation exchange HPLC instruments namely, the Medconn MQ-3000 in Normal Mode (NM), Lifotronic H100Plus in Variant Mode (VM), Mindray H-120 in Standard Mode (SM) and VM and the ARKRAY ADAMS A1c × HA-8110 in Quick Mode (QM) and SM for the measurement of HbA 1c . Methods Certified Clinical and Laboratory Standards Institute (CLSI) Evaluation Protocols were employed to assess precision (EP-5-A3), accuracy (EP-9-A3), linearity (EP-6), carryover (EP-10), as well as the interference of hemoglobin variants and other potential analytical interferences. Results With patient samples at concentrations of 43 mmol/mol (6.1 %) and 83 mmol/mol (9.7 %) each instrument CV was <1.2 % in SI units (<0.6 % in NGSP units). All instruments met the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) certification criteria, and all instruments met National Glycohemoglobin Standardization Program (NGSP) certification criteria with at least 5/7 Certified Secondary Reference Measurement Procedures (SRMP), except for the H100Plus compared to Premier Hb9210 and Roche Tina-quant Hemoglobon A1c Gen.3 on cobas c 513, and for the H-120 SM compared to the Sebia CAPILLARYS 3 Octa method. Only the ARKRAY ADAMS A1c X HA-8110 in both modes showed no interference of any from the investigated interferents. Conclusions The analytical performance of all 4 instruments, with respect to precision and standardization, met the established acceptance criteria. Nevertheless, the MQ-3000, H100Plus, and H-120 each exhibited interference with at least one of the evaluated parameters. In addition for these three instruments, further refinement of the software and accompanying user manual remains warranted.